linux-stable.git/tools/include/nolibc, branch linux-6.17.y

tools/nolibc/dirent: avoid errno in readdir_r

2025-12-18T12:59:28+00:00

[ Upstream commit 4ada5679f18dbbe92d87c37a842c3368e6ab5e4a ]

Using errno is not possible when NOLIBC_IGNORE_ERRNO is set. Use
sys_lseek instead of lseek as that avoids using errno.

Fixes: 665fa8dea90d ("tools/nolibc: add support for directory access")
Signed-off-by: Benjamin Berg 
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc/stdio: let perror work when NOLIBC_IGNORE_ERRNO is set

2025-12-18T12:59:28+00:00

[ Upstream commit c485ca3aff2442adea4c08ceb5183e671ebed22a ]

There is no errno variable when NOLIBC_IGNORE_ERRNO is defined. As such,
simply print the message with "unknown error" rather than the integer
value of errno.

Fixes: acab7bcdb1bc ("tools/nolibc/stdio: add perror() to report the errno value")
Signed-off-by: Benjamin Berg 
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: handle NULL wstatus argument to waitpid()

2025-12-18T12:59:14+00:00

[ Upstream commit 812f223fe9be03dc22abb85240b6f075135d2386 ]

wstatus is allowed to be NULL. Avoid a segmentation fault in this case.

Fixes: 0c89abf5ab3f ("tools/nolibc: implement waitpid() in terms of waitid()")
Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: add stdbool.h to nolibc includes

2025-10-15T10:03:37+00:00

[ Upstream commit 2d965c1ae4135ed6f505661458f6dabd39488dac ]

Otherwise tests compiled with only "-include nolibc.h" will fail with
"error: unknown type name 'bool'", even though a stdbool.h is available
from nolibc.

Fixes: ae1f550efc11 ("tools/nolibc: add stdbool.h header")
Fixes: f2662ec26b26 ("selftests: kselftest: Create ksft_print_dbg_msg()")
Reported-by: Mark Brown 
Closes: https://lore.kernel.org/lkml/833f5ae5-190e-47ec-9ad9-127ad166c80c@sirena.org.uk/
Signed-off-by: André Almeida 
[Thomas: add Fixes tags and massage commit message a bit]
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: make time_t robust if __kernel_old_time_t is missing in host headers

2025-10-15T10:03:36+00:00

[ Upstream commit 0ff52df6b32a6b04a7c9dfe3d7a387aff215b482 ]

Commit d5094bcb5bfd ("tools/nolibc: define time_t in terms of
__kernel_old_time_t") made nolibc use the kernel's time type so that
`time_t` matches `timespec::tv_sec` on all ABIs (notably x32).

But since __kernel_old_time_t is fairly new, notably from 2020 in commit
94c467ddb273 ("y2038: add __kernel_old_timespec and __kernel_old_time_t"),
nolibc builds that rely on host headers may fail.

Switch to __kernel_time_t, which is the same as __kernel_old_time_t and
has existed for longer.

Tested in PPC VM of Open Source Lab of Oregon State University
(./tools/testing/selftests/rcutorture/bin/mkinitrd.sh)

Fixes: d5094bcb5bfd ("tools/nolibc: define time_t in terms of __kernel_old_time_t")
Signed-off-by: Zhouyi Zhou 
[Thomas: Reformat commit and its message a bit]
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: avoid error in dup2() if old fd equals new fd

2025-10-15T10:03:23+00:00

[ Upstream commit d1ff0e2d13d6ac3a15be7870e15216726b0a809a ]

dup2() allows both 'old' and 'new' to have the same value, which dup3()
does not. If libc dup2() is implemented through the dup3() system call,
then it would incorrectly fail in this case.

Avoid the error by handling old == new explicitly.

Fixes: 30ca20517ac1 ("tools headers: Move the nolibc header from rcutorture to tools/include/nolibc/")
Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/r/20250820-nolibc-dup2-einval-v2-1-807185a45c56@linutronix.de
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: fix error return value of clock_nanosleep()

2025-10-15T10:03:19+00:00

[ Upstream commit 1201f6fb5bfdbd10985ac3c8f49ef8f4f88b5c94 ]

clock_nanosleep() returns a positive error value. Unlike other libc
functions it *does not* return -1 nor set errno.

Fix the return value and also adapt nanosleep().

Fixes: 7c02bc4088af ("tools/nolibc: add support for clock_nanosleep() and nanosleep()")
Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/r/20250731-nolibc-clock_nanosleep-ret-v1-1-9e4af7855e61@linutronix.de
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Sasha Levin

tools/nolibc: define time_t in terms of __kernel_old_time_t

2025-07-13T14:58:34+00:00

Nolibc assumes that the kernel ABI is using a time values that are as
large as a long integer. For most ABIs this holds true.
But for x32 this is not correct, as it uses 32bit longs but 64bit times.

Also the 'struct stat' implementation of nolibc relies on timespec::tv_sec
and time_t being the same type. While timespec::tv_sec comes from the
kernel and is of type __kernel_old_time_t, time_t is defined within nolibc.

Switch to the __kernel_old_time_t to always get the correct type.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250712-nolibc-x32-v1-1-6d81cb798710@weissschuh.net
Acked-by: Willy Tarreau

tools/nolibc: drop s390 clang target override

2025-07-08T07:24:00+00:00

tools/scripts/Makefile.include now has the same override,
removing the need for the one in the nolibc Makefile.

Drop the superfluous custom override.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250620-tools-cross-s390-v2-2-ecda886e00e5@linutronix.de
Signed-off-by: Thomas Weißschuh

tools/nolibc: avoid false-positive -Wmaybe-uninitialized through waitpid()

2025-07-07T13:24:35+00:00

The compiler does not know that waitid() will only ever return 0 or -1.
If waitid() would return a positive value than waitpid() would return that
same value and *status would not be initialized.
However users calling waitpid() know that the only possible return values
of it are 0 or -1. They therefore might check for errors with
'ret == -1' or 'ret < 0' and use *status otherwise. The compiler will then
warn about the usage of a potentially uninitialized variable.

Example:

	$ cat test.c
	#include 
	#include 

	int main(void)
	{
		int ret, status;

		ret = waitpid(0, &status, 0);
		if (ret == -1)
			return 0;

		printf("status %x\n", status);

		return 0;
	}

	$ gcc --version
	gcc (GCC) 15.1.1 20250425

	$ gcc -Wall -Os -Werror -nostdlib -nostdinc -static -Iusr/include -Itools/include/nolibc/ -o /dev/null test.c
	test.c: In function ‘main’:
	test.c:12:9: error: ‘status’ may be used uninitialized [-Werror=maybe-uninitialized]
	   12 |         printf("status %x\n", status);
	      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	test.c:6:18: note: ‘status’ was declared here
	    6 |         int ret, status;
	      |                  ^~~~~~
	cc1: all warnings being treated as errors

Avoid the warning by normalizing waitid() errors to '-1' in waitpid().

Fixes: 0c89abf5ab3f ("tools/nolibc: implement waitpid() in terms of waitid()")
Signed-off-by: Thomas Weißschuh 
Acked-by: Willy Tarreau 
Link: https://lore.kernel.org/r/20250707-nolibc-waitpid-uninitialized-v1-1-dcd4e70bcd8f@linutronix.de
Signed-off-by: Thomas Weißschuh